Field of the Invention
This invention relates to techniques and compositions useful for stabilizing reagents utilized in specific binding assays, such as immunoassays, that utilize enzyme complementation to generate a detectable signal.
Description of the Background
A number of immunoassays and other binding assays have recently been described that utilize the reassociation of polypeptide fragments to form active enzymes as a step of generating a detectable signal utilized to determine the amount of analyte present in an assay mixture. Several of these assays propose utilizing the enzyme .beta.-galactosidase as the enzyme being formed by complementation.
However, the stability of reagents based on fragments of .beta.-galactosidase has been discovered to be less than desirable. There is a gradual and significant loss of activity of the reformed enzyme as storage time of the fragments increases.
Accordingly, there remains a need for stabilization of reagents utilized in enzyme complementation assays based on the enzyme .beta.-galactosidase.